Gyration Mouse

I have a gyration mouse and I managed to spill tea over it. I can't find a link to the gyration website, but someone is selling one on ebay (auction number 220077608328 so you can see which model it is).

It still works but the right hand button doesn't press down properly. I imagine that some tea has dried inside the mouse and is clogging up the small space which the button moves into when it is clicked.

I have tried to dismantle the mouse to clean out any muck but am not being very successful. As this is a relatively expensive mouse I don't want to break it, but I would also like it to click properly!

If anyone has the same mouse and knows how to take it apart safely, please advise and rep will be awarded!